Iterating by reference on a C++ vector with foreach

Question

Does it make any sense to do something like:

void my_fun(std::vector<int>& n)
    {
        for (int& i : n) 
            {
                do something(i);
            }
    }

compared to a normal foreach loop without the reference? Would the value be passed by copy otherwise?

Yes, if you do not use a reference you get a copy. – NathanOliver Dec 10 '21 at 16:53 — NathanOliver, Dec 10 '21 at 16:53
if possible it should be `for (const int& i : n)` – 463035818_is_not_an_ai Dec 10 '21 at 17:03 — 463035818_is_not_an_ai, Dec 10 '21 at 17:03

score 0 · Accepted Answer · answered Dec 10 '21 at 16:56

0

It does what you think it does assuming that the signature of do_something is void do_something(int& i).

If you don't put the ampersand in the range-based for-loop you'll get a copy.

answered Dec 10 '21 at 16:56

jwezorek

1 Answers1